The Investigation of the Effects of Sunlight Simulated Drying and Pulsed Moderate Electric Field Assisted Extraction Processes in Handling of Color Matters from Red Pepper

Project no. 23539 · Status: Kapanmış · 2021

Summary

In this thesis, the effects of the drying processes carried out by the Daylight Simulated Drying (DSD) system and the extraction processes performed by the Pulsed Moderate Electric Field (PMEF) system on the quality and performance properties were investigated in handling of color matters from red pepper.During drying stage, red pepper samples were dried in the custom designed DSD system assisted with hot air (HA) and infrared (IR) heating sources, day light (DL) and led (LED) types of light, in six different drying modes. Drying processes were conducted at the temperature of 55 °C and the air velocity of 1.5 m/s to diminish the final moisture content to below 10%. The best thin layer model characterizing the drying characteristics of red pepper ( Verma et al. for HA, HA+DL, IR+DL HA+LED; Diffusion model for IR, IR+LED) were determined. In addition, the loss in the red color component, total antioxidant activity, color characteristics and performance characteristics were found. The lowest loss in the red color component and the highest total antioxidant activity were obtained in the drying processes performed with LED light. In addition, in the processes performed with the assisted of daylight, the loss in the red color component was lower and the total antioxidant activity were higher compared to the drying processes carried out in the absence of light. In terms of color characteristics, similar to other quality characteristics, it was determined that the LED light preserved the colors of red pepper. For the same light source, the effect of heating source was not effective on on the loss of red color component and total antioxidant activity (p<0.05).In order to obtain the color component from red pepper powder in the extraction stage, experiments were carried out with different pulse time (138-562 ms), frequencies (172-1727 Hz) and pulse types (bipolar and unipolar) in the custom designed Pulsed Moderate Electrical Field (PMEF) system. Its alternativeness compared to the traditional methods was investigated. PMEF was applied at the constant temperature of 40 °C for 20 min. with the sample solvent ratio of 1:8 (w/v). The most suitable PMEF condition was determined as 398 ms pulse time and 1500 Hz frequency in bipolar pulse type by taking criteria of maximum extraction efficiency (red color component), maximum total antioxidant activity and maximum energy efficiency.It is thought that this thesis will contribute valuable data to the industry and literature about using DSD system and the PMEF system in the drying and extraction stages of the plants especially in the use of production of color components.

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